Associate Professor and Chief, Division of Oral and
Maxillofacial Surgery
University of Florida Health Science Center
Jacksonville, Florida
They are to be attached by the patient himself in the morning and removed each evening or as desired at locations that the patient has been taught to remember antifungal lozenges ketoconazole 200 mg with visa. The same microchip also controls optic isolation chips to allow using a single power amplifier for all channels anti fungal rash cheap ketoconazole 200mg free shipping. The additional two stimulation channels (at the paraspinals for trunk stability) play a major role in enhancing standing time fungus video 200mg ketoconazole visa, ambulation distances fungus gnats nose cheap 200mg ketoconazole with amex, and speeds as compared with four channel systems fungus cordyceps buy ketoconazole 200mg online. Higher pulse width speeds up the rate of muscle fatigue and therefore reduces the maximal ambulation distance (see Table 31 anti fungal uti buy 200 mg ketoconazole with visa. It also sends into the body more electrical charge than is needed and requires higher battery power and hence higher battery weight antifungal medicine for dogs purchase ketoconazole 200 mg online. The inter-pulse repetition rate (frequency) is set higher than the average pulse rate in the able-bodied individual antifungal soap target buy discount ketoconazole 200mg online, but is still kept as low as possible (22 to 24 pulses/sec) to reduce rate of fatigue (see Table 31. It is determined by considerations of fatigue, tetanization, and force (note that while standing or walking, the body weight dampens vibrations considerably). Higher frequencies also imply that a higher electrical charge enters the body and requires higher battery power and heavier batteries. Furthermore higher pulse rates speed up the rate of muscle fatigue to reduce duration and range of ambulation. Both pulse widths and rates, while constant, can be adjusted if necessary (see Figure 31. Therefore, a combination of a short pulse duration, low stimulation levels, and low pulse rate is essential to reduce muscle fatigue, thus extending walking distance (walking time) per walk [5]. The consequences of lower battery power needs, of lower system weight, and of the resultant effect on compactness are of course also significant for a patient-borne system and for user friendliness, especially, in a body-borne system. The menus are those for standing up, for right step, for left step, and for sitting down (see Figure 31. Pulse-amplitude shaping is dynamic and varies for each of the six stimulation channels and as per each menu, as does the distribution of output signal to each output channel [5,11]. Finally, two electrodes are placed over the right paraspinals at right and two at left, for upper trunk stability in patients with lesions at T7 or higher (to be placed approximately 1 in. These alternatives involve other branches of the sciatic nerve, which trigger the hip flexion reflex. However, when increasing the number of channels, say from six to eight, the patient must place (every morning) 16 electrodes instead of 12 and for a paraplegic patient this involves a lot of additional effort and time. Paraspinal signal envelopes correspond in shape to quadriceps channels except for peaks. Hence, human factor considerations imply to limit the system to the most important functions (channels) as far as performance is concerned. Pulse-amplitude shaping is dynamic and varies for each of the six stimulation channels and per each menu, as does the distribution of output signal to each output channel [6,27]. The time variation of the pulse amplitudes in each menu and per each channel, as in Figure 31. At the end of this period T, stimulation to the left common peroneal stops and the left quadriceps and left paraspinals/gluteus are stimulated. However, during the step period, the level of stimulation at the right quadriceps is automatically increased by the sequencing program to compensate for the fact that full body weight is borne by the right leg over that period. If a right step is selected, then the same menu is employed, with a reversal of roles of right and left. When a sit-down menu is selected, then the sequencing program first triggers an audible and a visual warning to allow the patient to abort the sit-down if he is not ready to sit and to allow for time to 31-10 Biomedical Engineering Fundamentals reach a chair and to comfortably sit down. Also, at that time, stimulation to the quadriceps is increased to compensate for possible weakening of the quadriceps that may have caused the patient to decide to sit. The microchip also controls optic isolation chips to allow using a single power amplifier for all channels. This allows the Parastep to employ six rather than the usual four stimulation channels and to integrate them to reduce system weight, while facilitating full patient control of all channels. The additional two stimulation channels (at the paraspinals, for trunk stability) play a major role in enhancing standing time, ambulation distances, and speeds as compared to four channel systems. They require only a light single and quick (short) finger touch without changing hand position on the bars. Adaptation and learning of balancing and of menu selection (only two menus during walking; of right and of left step, activated at right or left handlebar), is very easy and fast. Therefore, the patient does not have to produce a specific produce upper-body above-lesion (shoulder) movement to select a particular menu. In the commercial Parastep, the stimulation level is controlled by the touch buttons at the left and right hand side of the walker. Out of 10 possible level increments that are color marked most patients use one of the 3 lowest levels to start their walk, in order to minimize rate of fatigue. Furthermore, since any stimulation electrode-pair activates many hundreds of motor neurons simultaneously, all resultant action potentials are fully synchronized and appear as one very strong action potential due to this combined and synchronized firing (see Figure 31. It can thus serve to detect progression of fatigue and serve to adjust stimulation levels accordingly. It thus allows the users to balance their body by slight shoulder and arm movements to better balance during standing and walking. The users are able to easily and rather naturally change direction of walking, at will, through shoulder positioning by which they turn their steps. One major function of the walker is during the stand-up phase from a seated position. The patient then gets up 31-12 Biomedical Engineering Fundamentals with the arms leaning on the walker. All these reasons indicate the crucial role of walkers toward achieving independent standing and walking. Hence, the criteria for a patient to be admitted to train and to use the Parastep standing/ambulation system are as follows [7,27,29]: 1. The patient must be in good general health and with a complete traumatic spinal cord lesion at levels no higher than C-7 and no lower than T-12. No recent history of long bone stress fractures, osteoporosis, or severe hip or knee joint disease. A bone density test is advisable in case of women over 40 or patients who are many years (10 or more) beyond date of injury. Adequate trunk stability so that once quadriceps are stimulated, the patient can hold his upper trunk upright while supporting himself with a walker. The patient demonstrates appropriate muscle contractions in response to stimulation (absence of such response usually implies some lesions below T-12). Standing tolerance: the patient has adequate fatigue tolerance to practice and perform standing and walking functions after initial training. Future systems may circumvent the need for finger control via speech recognition to allow patients lacking hand/finger control to use the system. Sufficient upper body and arm strength to lift oneself up to the walker for a second or two without stimulation and to grasp chair when stimulation is stopped for any reason. Motivation: the patient demonstrates and expresses appropriate desire and commitment to the training program. Also, interference of stimulation signal with an electronic cardiac pacemaker must be avoided. Distances and speed vary widely and even distances (and speeds) well below the averages mentioned in this chapter may be a major achievement for some patients, depending on their general health, level of lesion, age, and any other limitations they may have. The author had trained a 62-yearold T-3/T-4 complete paraplegic patient (gunshot wounds) who was in the wheelchair for 40 years and never been stimulated. This patient stood up in his first session and took 12 steps in his third one-hour session. This should not just be verbal, but also in terms of helping the candidate stand/walk at home after or between training sessions by walking next to him/her to be able to prevent the patient from a possible fall, and moving (sharp) obstacles from the way. The patient should have at least one strong armchair (possibly a metal chair) with arm rests at an adequate height for the patient to be able to get up and sit down independently of the walker. Some patients do initially need help in placing the lower paraspinal or gluteus electrodes on the skin. It is very advisable that a family member or friend should observe at least part of one training session. The skin electrodes need be replaced once every 2 weeks (or less, if contact to skin is inadequate). Bad electrodes or broken electrode connectors are the main reasons for stimulation failure. This author is familiar with Parastep training programs that involve 5 to 6 h a day of supervised training for 5 or 10 consecutive days, of Parastep programs of one hourly session every week or every 2 weeks for over 1 year, of Parastep programs of three 1-h sessions a week for 11 weeks (Klose et al. However, they differ widely in cost and in the required commitment of time by the patient. Therefore, the decision on which kind of program to attend is usually not a matter of choice. Regardless of the training program, it is of utmost importance that the patient complements each supervised training session with after-hour home exercise of at least 15 min (many programs require much more). In almost all training programs, training starts with reconditioning and strengthening of the muscles involved and also of arm muscles. First, the quadriceps muscles, which are those that are the most involved in stand-up and in standing require strengthening. In many programs, monitoring of heart rate and of blood pressure is done during treadmill training. Parallelbar standing and walking are sometimes used at the initial stages, during a muscle-strengthening phase. But parallel-bar exercise does not help in learning to rely on and to balance oneself with the walker and may therefore be counter productive. Muscle strengthening while seated is a very major part of the home exercise throughout training, but takes place only in the first or second supervised sessions. It is psychologically most important to stand a patient up, even for 20 to 30 sec (as long as is safe) even in the first session. This and taking of the first few steps (even 2 or 3) early on are great motivators. Hence, the first step should be taken after the patient can stand safely (with a walker) for about 3 min. Eventually, training and muscle strengthening should aim at standing for 10 min or more and walking for as long as is possible. At the last stages of training, patients should be taught to fall, by sudden power shutdown (they will learn to avoid an actual fall through proper use of walker). They will also learn to lift themselves up from the ground with no help, to walk on rough ground, and on reasonable slopes. The most advanced T-9 to T-12 patients can then train on using elbow-support cane. Continuous walking after end of training on a near-daily basis, for at least 45 min a day (not necessarily in one session per day) is essential for progress and for improved performance. Psychologically and motivationally, it is desired that the patient gets up (to a walker, not to parallel bars) in the first or second session. However, this should not defer rigorous muscle strengthening in future sessions (actually, until end of the training program). Studies conducted in different clinical settings reported distances walked by individual users ranging from a few feet to over a mile at a time, with the average distance being around 1450 ft (450 m/walk) for fully trained patients in certain training programs [32,33]. Improvements in performance will be very noticeable 1 or 2 years after end of formal training. The author expects this to be the case too for the Vicenza (Italy) training program. The Miami Project to Cure Paralysis of the University of Miami reports average ambulation distances for Parastep users of 115 m/walk at a mean pace of 5 m/min, at the end of the training program of 33 sessions over 11 weeks [31]. For the Parastep training program of daily sessions over 4 months at the Centro di Rehabilitazione di Villa Margherita in Argugnano, Vicenza, Italy, an average distance of 444 m per walk was reported, at a mean speed of 14. However, continuous use may be higher for patients whose performance at end of training is considerably higher. The Vicenza program reports zero dropout 14 to 39 months after end of training [32]. However, these do not include performance data or medical or psychological patient evaluation on that system. A 14 min video of complete thoracic-level paraplegic patients, while walking with the Parastep system, is shown in Medical and psychological evaluation that were published on Parastep users, show several medical and psychological benefits to walking with the Parastep. We discuss the medical and physiological evaluation results here, while psychological evaluation outcomes are summarized in Section 31. Lower-Extremity Blood Flow: A study performed as a part of the Miami Project, to Cure Paralysis of the Departments of Neurological Surgery and of Orthopedics and Rehabilitation of the University of Miami, authored by Nash et al. Cerrel-Bazo reported (verbally) to this author similar improvements (at the Vicenza program in Italy). Other Cardiovascular Effects: the above 12-patient study at the Miami Project of the University of Miami [34] has shown that the average resting heartbeat of Parastep users decreased from 70. Physiological Responses to Peak Arm Ergometry: A study on physiological responses by 15 Parastep users [27] to peak-arm ergometry exercises have shown that average time to fatigue has improved from 15. The patients (12 men, 3 women) ranged in age from 21 to 45, in years from injury from 0. Muscle Mass: A significant increase (10 to 22%) in high circumference was measured on Parastep users after 3 to 6 months of training at the University of Illinois/Michael Reese Hospital training program in Chicago [5]. In the authors experience in 19 years of observing well over 100 patients training with or using the Parastep system, almost all patients who complained of spasticity commented on either considerable or some improvement in spasticity. The improvement in spasticity is important with regard to the detrimental effect of medications (Baclofen, Valium, Lioresal) on alertness and fatigue as medication doses can then be reduced in many cases [5]. This happens right after injury and may be aggravated when the patient does not put weight on the legs. Pressure Ulcers (Decubitus Ulcers): Almost all paraplegics suffer from decubitus ulcers. Improved blood circulation at below the lesion is most likely the cause for this [27]. The results of the study show that all five patients who were initially at the mild or moderate depression score levels (one was initially even beyond the moderate range) did improve significantly. The psychological evaluation results, as in the present section, are summarized in Table 31. It also discusses its design, operation, admission criteria, contraindications, and training. Training programs for that system exist in many hospitals and rehabilitation centers. As was discussed above, upon completion of 4 months of daily training, ambulation distances for the Parastep system were reported to average 444 [32] or 115 m/walk in a 33-session 11-week program [31]. Medical benefits have been documented, in terms of greatly increased blood flow to the lower extremities [34], reduced spasticity [29], reduced incidence of decubiti [27], increased thigh circumference [27], and of psychological benefits (improved self-concept and depression scores) [37]. However, the circulatory benefits and the other medical and psychological befits should play an important role, for patients, for physicians, and for insurance companies involved. All this does not detract in any way from the urgent need to repair the spinal cord through regeneration. It can always be and will be improved, but its performance even now is usually pretty good. The second group produces flexible wires that are inserted into the cortex and provide signals also for months and sometimes years [4]. The holy grail of all these efforts is the restoration of movement to the paralyzed. For example, quadriplegics need to use their hands, and cortical control of functional neuromuscular stimulation devices would appear to be the answer to this need. Similarly for amputees, robotic technologies will be wed with cortical control signal technologies for successful control of artificial limbs. Herculean efforts have been expended by all workers in this field to provide single unit recordings in the belief that the precision needed for control of digits is found only in the firing patterns of cortical single units recorded from primates. While not doubting this conclusion, less precise control may be sufficient for some prosthetic applications. First, let us look more closely at these three electrode categories and discuss the pros and cons. Nevertheless, I will try to be as impartial as I can and assess the facts as published and known to me. The first three investigators use tine type electrodes that are either the 100-pin array (devised by Dick Norman), and used by Donoghue and colleagues [2], or the Michigan probe used by Schwartz et al. Longevity is of prime importance in a chronic electrode that is to be implanted in a young adult human for a lifetime that can extend beyond 50 years. Nevertheless, there is yet no firm evidence of that, so stability still remains important. It ought to be easier to train one unit, than an unruly classroom of poorly correlated units.
Syndromes
Excessive bleeding
Cytomegalovirus
Use a wheelchair or stay in bed for a long time
Precancerous polyps (nodes)
CO2 (carbon dioxide)
Colposcopy-directed biopsy to confirm the condition
Flushing
Body-wide infection (sepsis)
Headaches
Optimally antifungal vitamins ketoconazole 200 mg cheap, strength testing would be based on the "worst-case" functional performance demands required by an individual in his or her daily life opportunistic fungi definition generic ketoconazole 200 mg fast delivery. In the absence of such data antifungal otc oral order ketoconazole 200 mg without prescription, current strategy is to choose the instruments and techniques that maximally stress the system under a set of representative conditions that either (a) seem logical based on knowledge of the task fungal nail salon discount ketoconazole 200mg line, or (b) have been reported as appropriate and reliable for the population of interest fungal cream order ketoconazole 200 mg otc. In addition fungal infection buy ketoconazole 200 mg low price, the subject must be observed for muscle group substitutions and "trick" movements fungus detox generic ketoconazole 200mg without prescription. The maximum movement speed that can be achieved represents another unique performance capacity of an identified system that is responsible for producing motion anti yeast vegetables buy discount ketoconazole 200mg on-line. Everyday living, work, and sport tasks are commonly described in terms of the speed requirements. For physical tasks, such descriptions translate to translational motion speeds. Two body parts may be moving through an arc with the same speed of movement; however, if one part has a greater mass, its muscles must develop more tension per unit of time to move the heavier body part at the same speed as the lighter body part. The terms velocity and speed are often used interchangeably; however, the two quantities are frequently not identical. General velocity and acceleration measurements are beyond the intent of this chapter. Reaction speed and response speed are other related variables also not considered. In addition to these and other physiological factors, speed can be reduced by factors such as friction, air resistance, gravity, unnecessary movements, and inertia [Jensen and Fisher, 1979]. Typically, if the whole body is moving linearly in space as in walking or running, a point such as the center of gravity is picked, and translational motion is measured. As the focus here is on measuring isolated neuromuscular performance capacities, the angular metric is emphasized. Angular speed of a body segment is obtained by: angular speed = change in angular position/change in time, = t (76. Another type of speed measure applies to well-defined (over fixed angle or distance) cyclic motions. Here repetitions per unit time or cycles per unit time measures are sometimes used. However, in almost every one of these situations, speed can be expressed in degrees per second or meters per second. The latter units are preferred because they allow easier comparison of speeds across a variety of tasks. The only occasion when this is difficult is when translation motion is not in a simple straight line, such as when a person is performing a complex assembly task with multiple subtasks. The issue of whether to express speed as maximum, averaged, or instantaneous values must also be decided, based on which measure is a more useful indicator of the performance being measured. In addition to numerical reporting of speed data, time-history graphs of speed may be helpful in comparing some types of performance. With rapid angular joint movements, switch plates or electrogoniometers with electronic timing devices are required. Speeds can also be computed from the distance or angle and time data available from cinematography, optoelectric movement monitoring systems, and videotape systems. Some dynamic strength testing devices involve presetting a load and measuring the speed of movement. In addition, accelerometers can be used to measure acceleration directly, and speed can be derived through integration. However, piezoelectric models have no steady-state response and may not be useful for slower movements. Triaxial accelerometers are commercially available that contain three premounted accelerometers perpendicular to each other. Multiple accelerometer outputs require appropriate processing to resolve the vector component corresponding to the desired speed. Accelerometers are most appropriately used to measure acceleration when they are mounted on rigid materials. Accelerometers Measurement of Neuromuscular Performance Capacities 76-17 have the advantage of continuously and directly measuring acceleration in an immediately usable form. Because they require soft tissue fixation and cabling or telemetry, they may alter performance and further error may be induced by relative motion of the device and tissues. The systems are moderately expensive (see discussion of accelerometers in Robertson and Sprigings [1987]). Because speed of movement data are calculated from displacement and temporal data, a key issue is minimizing error that might result from collecting this information. Error can result from inaccurate identification of anatomical landmarks, improper calibration, perspective error, instrument synchronization error, resolution, digitization error, or vibration. The sampling rate of some of the measurement systems may become an issue when faster movements are being analyzed. In addition, the dynamic characteristics of signal conditioning systems should be reported. Endurance can apply to the body as a whole, a particular body system, or to specific neuromuscular functional units. High levels of endurance imply that a given level of performance can be continued for a long time period. Although many central and peripheral anatomic sites and physiologic processes contribute to a loss of endurance, endurance of neuromuscular functional units is also referred to as muscular endurance. Furthermore, the same relationships between absolute and relative endurance and strength are correlated by type of contraction; in other words, there is a strong positive correlation between isotonic strength and absolute isotonic endurance and vice versa for strength and relative isotonic endurance. The same types of relationships exist for isometric strength and isometric endurance [Jensen and Fisher, 1979]. Slow-twitch fibers (S) generate low levels of tension slowly, and are highly resistant to fatigue. Strength testing requires short duration and maximal contractions; therefore, to differentiate strength and endurance testing, the duration and intensity of the contractions must be considered. Because strength affects endurance, all of the factors discussed previously as influencing strength, also influence endurance. Endurance time, or the time for muscles to reach fatigue, is a function of the contraction force or load [von Rohmert, 1960]. Also, as speed increases, particularly with activities involving concentric muscle contractions, endurance decreases. When the focus is endurance, the other factors of force or torque, speed, and joint angle, can be described as conditions under which endurance is measured. One endurance-related measure uses either the number of repetitions that can be performed at 20, 25, or 50% of maximum peak torque or force. The units used to reflect endurance in this case are number of repetitions at a specified torque or force level. One difficulty with this definition has been described previously, that is, the issue of relative vs. Rothstein and Rose [1982] demonstrated that elderly subjects with selected muscle fiber type atrophy were able to maintain 50% of their peak torque longer than young subjects. However, if a high force level is required to perform the task, then the younger subject would have more endurance in that particular activity [Rothstein, 1982]. Another difficulty is that the "repetition method" can be used only for dynamic activities. If isometric activities are involved, then the time an activity can be sustained at a specified force or torque level is measured. Yet another method used to reflect endurance is to calculate an endurance-related work ratio. In this case, the total amount of work performed in the first five repetitions is compared with the total amount of work performed in the last five repetitions of a series of repetitions (usually 25 or more). An additional limitation of using these endurance ratios is that work cannot be determined in isometric test protocols. Overall, the greatest limitation with most endurance-related approaches is that the measures obtained cannot be used to perform task-related assessments. In a workplace assessment, for example, one can determine how long a specific task (defined by the conditions of load, range, and speed) needs to be performed. Time reflects changes in endurance as the result of disease, disuse, training, or rehabilitation and also can be linked to task demands. As in strength testing, endurance tests can involve simple, low-level tasks or whole-body, higher-level activities. The simplest method of measuring endurance is to define a task in terms of performance criteria and then time the performance with a stopwatch. A subject is given a load and a posture and asked to hold it "as long as possible" or to move from one point to another point at a specific rate of movement for "as long as possible. This test measures how long a person can sustain his or her torso in a suspended prone posture. The individual is not asked to perform a maximal voluntary contraction, but an indirect calculation of load is possible [Smidt and Blanpied, 1987]. An example of a dynamic endurance test is either a standardized or nonstandardized, dynamic isoinertial (see description in Section 76. In other words, the subject is asked to lift a known load with a specified body part or parts until defined conditions can no longer be met. Conditions such as acceleration, distance, method of performance, or speed may or may not be controlled. The more standardized of these tests, particularly those that involve lifting capacity, are reported and projections about performance capacity over time are estimated [Snook, 1978]. Ergometers and some of the isokinetic dynamometers discussed earlier measure work, and several can calculate endurance-related ratios. Except for test duration and rest intervals, attention to the same guidelines as described for strength testing is currently recommended. First, it is important to note that reliability and validity are not inherent qualities of instruments, but exist in the measurements obtained only within the context in which they are tested. Second, reliability and validity are not either present or absent but are present or absent along a continuum. Third, traditional quantitative measures of reliability might indicate how much reliability a given measurement method demonstrates, but not how much reliability is actually needed. Fourth, technology has advanced to the extent that it is generally possible to measure physical variables such as time, force, torque, angles, and speed accurately, repeatably, and with high resolution. Finally, clinical generalizability of human performance capacity ultimately measures results from looking at the body of literature on reliability as a whole and not from single studies. For these types of variables, results of reliability studies basically report that (1) if the instrumentation is good, and (2) if established, optimal procedures are carefully followed, then results of repeat testing will usually be in the range of about 5 to 20% of each other. This range of repeatability depends on (1) the particular variable being measured. If a specific 76-20 Biomedical Engineering Fundamentals application requires extreme repeatability, then a reliability study should be conducted under conditions that most closely match those in which the need arises. Reliability discussions specific to the some of the focal measures of this chapter are presented in Amundsen [1990], Hellebrandt et al. Most validity studies have compared the results of one instrument to another instrument or to known quantities. This is the classical type of validity testing, which is an effort to determine whether the measurement reflects the variable being measured. In addition to traditional studies of the validity of measurements, the issue of the validity of the inferences based on the measurements is becoming increasingly important [Rothstein and Echternach, 1993]. That is, can the measurements be used to make inferences about human performance in real-life situations? Unfortunately, measurements that have not demonstrated more than content validity are frequently used as though they are predictive. The validity of the inferences made from human performance data needs to be rigorously addressed. A general limitation is that performance variables are not fixed human attributes. Another limitation is that population data are limited, and available normative data are, unfortunately, frequently extrapolated to women, older persons, and so on [Chaffin et al. Performance measurements may yield information about the current status of performance, but testing rarely indicates the cause or the nature of dysfunction. While, considerable information exists with regard to measuring performance capacities of human systems, much less energy has been directed to understanding requirements of tasks. The link between functional performance in tasks and laboratory-acquired measurements is a critical question and a major limitation in interpreting test data. Therefore, both the individual and the task must be considered when selecting measurement tools and procedures [Chaffin et al. More recent systems engineering approaches [Kondraske, 2005] emphasize consideration of the performance envelope of a given system and suggest ways to integrate single measurement points that define the limits of performance of a given system [Vasta and Kondraske, 1997]. The additional dimension of endurance can be represented by displaying this envelope after performing an activity for different lengths of time. A higher-level, composite performance capacity, as is sometimes needed, could be derived by computing the volume enclosed by this envelope. Such representations also facilitate assessment of the given system in a specific task; that is, a task is defined as a point in this space that will either fall inside or outside the envelope. We want to reduce it to comprehensible units and then enhance it, reproduce it, restore it, and predict it. Hence, an array of instruments and methods has emerged to measure various aspects of human performance. Yet, single measurements will not suffice; multiple measurements of different aspects of performance will be necessary to fully characterize human movement. Defining Terms Endurance: the amount of time a body or body segments can sustain a specified static or repetitive activity. Muscle strength: the maximal amount of torque or force production capacity that a muscle or muscle groups can voluntarily exert in one maximal effort, when type of muscle contraction, movement velocity, and joint angle(s) are specified. Neuromuscular functional units: Systems (that is, the combination of nerves, muscles, tendons, ligaments, and so on) responsible for producing basic movements. Physical measurements as risk indicators for low back trouble over a one year period. Musculoskeletal Assessment: Joint Range of Motion and Manual Muscle Strength, 2nd ed. Analysis of strength tests and resistive exercises commonly used for low-back disorders. Factors contributing to the regulation and clinical assessment of muscular strength. Effects of isometric training in the force-time characteristics of muscle contractions. A multi-dimensional performance space model for the human knee extensor, Technical Report 94-001R. An approach to estimating performance capacity envelopes: knee extensor system example. Proceedings of the 19th Annual Engineering in Medicine and Biology Society Conference, pp. Further Information Journals: Clinical Biomechanics, Journal of Biomechanics, Medicine and Science in Sports and Exercise, Physical Therapy. Computerized system for quantitative measurement of sensorimotor aspects of human performance. In its widest context, movement is carried out by a sensory-motor system comprising multiple sensors (visual, auditory, proprioceptive), multiple actuators (muscles and skeletal system), and an intermediary processor which can be summarized as a multiple-input multiple-output nonlinear dynamic time-varying control system. This grand control system comprises a large number of interconnected processors and sub-controllers 77-1 77-2 Biomedical Engineering Fundamentals at various sites in the central nervous system of which the more important are the cerebral cortex, thalamus, basal ganglia, cerebellum, and spinal cord. It is capable of responding with remarkable accuracy, speed (when necessary), appropriateness, versatility, and adaptability to a wide spectrum of continuous and discrete stimuli and conditions. Certainly, by contrast, it is orders of magnitude more complex and sophisticated than the most advanced robotic systems currently available - although the latter also have what are often highly desirable attributes such as precision and repeatability and a much greater immunity from factors such as fatigue, distraction, and lack of motivation! First, it introduces several important concepts relating to sensory-motor control, accuracy of movement, and performance resources/capacities. Second, it provides an overview of apparatuses and methods for the measurement and analysis of complex sensorymotor performance. The overview focuses on measurement of sensory-motor control performance capacities of the upper-limbs and by means of tracking tasks. This system can be considered as a hierarchy of multiple interconnected sensory-motor controllers cited in the central processing and skills ("software") domains (cf. These controllers range from lowlevel elemental level controllers for control of movement around single joints, through intermediate-level controllers needed to generate integrated movements of an entire limb and involving multiple joints and degrees of freedom, and high-level controllers and processors to enable coordinated synergistic multi-limb movements and the carrying out of central executive functions concerned with allocation and switching of resources for execution of multiple tasks simultaneously. Accuracy is the most important of these and can be divided into four major classes: 1. Spatial accuracy - Required by tasks which are self-paced and for which time taken is of secondary or minimal importance and includes tracing. Spatial accuracy with time constraints - Identical to "spatial accuracy" except that, in addition to accuracy, speed of execution of task is also of importance. Because maximal performance capacities for accuracy and speed of movement cannot, in general, be realized simultaneously, the carrying out of such tasks must necessarily involve speed-accuracy tradeoffs [Fitts, 1954; Fitts and Posner, 1967]. The extent to which accuracy is sacrificed for increased speed of execution, or vice versa, is dependent on the perceived relative importance of accuracy and speed. Temporal accuracy - Required by tasks which place minimal demands on positional accuracy and includes single and multi-finger tapping and foot tapping. Spatiotemporal accuracy - Required by tasks which place considerable demand on attainment of simultaneous spatial and temporal accuracy.
Buy ketoconazole 200 mg low price. 5 Amazing Health Benefits Of Patchouli Oil.
Autopsy revealed a 1 antifungal quiz cheap ketoconazole 200 mg otc,190-g brain with moderate frontal and parietal and mild temporal atrophy antifungal ear drops uk buy generic ketoconazole 200 mg. Coronal sections revealed severe dilatation of the lateral ventricles and severe attenuation of the subcortical white matter (figure 2) fungus gnats on dogs buy ketoconazole 200mg online. Microscopically fungus king twom generic ketoconazole 200 mg amex, there was severe white-matter rarefaction with loss of both axons and myelin fungus gnats eat leaves purchase ketoconazole 200mg on line, and frequent neuroaxonal spheroids and pigmented glia and macrophages (figure 3) antifungal cream for baby purchase ketoconazole 200 mg free shipping. Two separate neuropathologists confirmed the diagnosis of adult-onset leukodystrophy with neuroaxonal spheroids and pigmented glia antifungal foot powder 200mg ketoconazole. A recent literature review reported that the age at onset varies from 15 to 78 years fungus gnats and fruit flies buy ketoconazole 200 mg online, with a mean of 42 years of age. The duration of symptoms ranged from 2 months to 34 years, with symptoms including dementia, apraxia, ataxia, urinary incontinence, and extrapyramidal symptoms. The differential diagnosis includes frontotemporal dementia, corticobasal degeneration, and other leukoencephalopathies such as metachromatic leukodystrophy, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, and Binswanger disease. This gray-matter involvement may reflect neuronal death due to lack of sustaining cortical/subcortical projecting fibers, or may also be due to white-matter damage to tracts that traverse these nuclei. Microscopy reveals widespread leukoencephalopathy with axonal spheroids and macrophages in affected white matter. The spheroids are best identified with Bielschowsky, Bodian, and antineurofilament immunostains. Zadikoff treated the patient in this case report, provided references, and made several revisions to this case report. Bigio made the pathologic diagnosis for this patient, provided the pathologic description in the case report, provided references, and provided the pathologic figures for this case report. Gitelman treated the patient in this case report and made substantial revisions to this case report. Pressman serves on the editorial team of the Residents and Fellows Section of Neurology, and writes for About. Accuracy of the clinical diagnosis of corticobasal degeneration: a clinicopathologic study. Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia can present as frontotemporal dementia syndrome. Adult onset leukodystrophy with neuroaxonal spheroids: clinical, neuroimaging and neuropathologic observations. The symptoms began abruptly 2 hours earlier during her daily work as a housekeeper when she suddenly noticed a "double tap" sound on each step of her right foot. She denied any history of trauma to the lumbar spine or to the affected lower extremity. Ankle and toe plantar flexion, knee flexion, as well as hip abduction, extension, and internal rotation, were normal. The Achilles tendon and patellar reflexes were elicited symmetrically (21) on both sides. Sensory examination demonstrated decreased sensation to pinprick on the dorsum of the right foot and the patient reported a vague discomfort in the lateral part of the right lower leg. She was able to walk unaided; however, she could not stand on the heel of her right foot. What is the most probable anatomic location of the lesion responsible for these symptoms? The presence of focal muscle weakness in a nonpyramidal distribution without evidence of corticospinal tract impairment. Several authors have described rare central causes of foot drop, such as lesions affecting the paracentral lobule1. Likewise, disorders of the neuromuscular junction or the muscles are usually excluded because they generally manifest with diffuse weakness affecting bulbar, proximal, or distal muscles. Therefore, foot drop is commonly attributed to lower motor neuron pathology and L5 radiculopathy is often suspected in the context of herniated nucleus pulposes or foraminal stenosis. The second most common cause is fibular (peroneal) neuropathy, particularly at the region of the knee. Preferential injury of fibular nerve fibers can also occur in the sciatic nerve, where the fibular division is separately encased from tibial fibers or at the lumbosacral plexus causing a clinical picture indistinguishable from true fibular neuropathy. The fibular division of the sciatic nerve is considered susceptible to injury because it comprises a smaller number of larger fascicles compared to the tibial division and supportive connective tissue is relatively sparse. Clinical examination is to a degree an exercise of logical deduction where muscles belonging to the same myotome but receiving innervation from different peripheral nerves are sequentially examined. In this setting, a diagnostic clue favoring fibular neuropathy is the preservation of ankle inversion. Specifically, ankle inversion is carried out by the posterior tibialis muscle that receives L5-S1 innervation from the tibial nerve. Moreover, ankle and toe dorsiflexion, as well as ankle eversion, are performed by fibular innervated muscles that likewise are partially supplied from the L5 root. Therefore, when ankle inversion is intact, this strongly suggests fibular neuropathy. Furthermore, in cases of L5 radiculopathy, toe extension tends to be more severely affected than ankle dorsiflexion because the extensor hallucis longus muscle receives the major bulk of its innervation from the L5 root. At this point, the exact site where fibular nerve fibers are damaged cannot be identified. The fibular nerve is extremely vulnerable due to its superficial course particularly at the fibular neck, where the nerve is covered only by subcutaneous fat and skin. Additionally, it is associated with conditions such as diabetes mellitus, alcohol abuse, malnutrition, polyarteritis nodosa and other systemic vasculitides, anorexia nervosa, bariatric surgery, and hereditary neuropathy with liability to pressure palsy. A subset of cases is due to compression from intraneural or extraneural masses such as ganglia, Schwannomas, neurofibromas, and osteochondromas. Normal tibial and sural studies, as well as the lack of denervation in nonfibular innervated muscles, rule out a coexisting lumbosacral plexopathy or L5 radiculopathy. Considering there was no history of trauma or compression at the fibular neck, other disorders that are Figure Electrodiagnostic testing, imaging, and intraoperative photograph (A) Right fibular motor conduction study to the extensor digitorum brevis. Neurology 84 February 17, 2015 57 associated with mononeuropathies should be excluded. Complete blood count, erythrocyte sedimentation rate, fasting blood glucose levels, and hepatic and renal function tests were normal. It was located along the anatomical course of the deep and superficial fibular nerves. The lesion showed low to intermediate signal intensity on T1-weighted images and high signal intensity on T2-weighted images. On T1-weighted images after gadolinium administration, the mass demonstrated a cystic appearance due to peripheral enhancement. The epineurium was incised and the content of the ganglion cyst consisting of jelly-like mucous material was removed. Postoperatively the patient displayed significant improvement and several weeks afterwards only minor weakness of foot dorsiflexion remained. Intraneural ganglia are benign fluidcontaining cystic masses most commonly found in the fibular nerve near the superior tibiofibular joint. A palpable mass is often noted in the region occasionally accompanied by local pain. Our case featured acute onset of symptoms during physical activity, which is rarely described in previous reports. Alternatively, the articular theory posits that fibular ganglia formation is the result of cystic fluid migration from the superior tibiofibular joint through the articular branch. At latter stages, proximal expansion may lead to involvement of the superficial peroneal nerve or even the sciatic nerve. Further support to the articular theory is the identification of a pathologic articular branch stemming from a nearby joint in cases of intraneural ganglia located in other nerves, such as the tibial and the median nerve. Consequently, the persistent pathologic communication between the superior tibiofibular joint and the fibular nerve needs to be addressed in order to avoid postoperative recurrences. Previous studies have shown that ligation of the articular branch is a crucial determinant of outcome. Long-term success of surgical treatment relies to a great extent on performing careful ligation of the pathologic articular branch, thereby eliminating the underlying pathogenetic mechanism. Rallis: outline of original manuscript, elaboration of clinical localization, differential diagnosis, revision of final draft. Skafida: electrodiagnostic testing, literature search, analysis of case discussion. Teaching NeuroImages: peroneal intraneural ganglion cyst: a rare cause of drop foot in a child. Acute onset of deep peroneal neuropathy during a golf game resulting from a ganglion cyst. Peroneal intraneural ganglia: the importance of the articular branch: a unifying theory. Peroneal intraneural ganglia: the importance of the articular branch: clinical series. In elementary school she had difficulty with hop-skip and keeping up with her peers. At age 10 years, she was noted to be unable to fully extend her elbows and was walking on toes. In college, she manifested slowly progressive lower limb weakness resulting in difficulty climbing stairs. She did not have visual symptoms, ptosis, facial weakness, dysarthria, or paresthesias. There is no history of parental consanguinity; her parents, 2 siblings, and the 7-year-old son had no muscle weakness. Her examination revealed generalized muscle atrophy and no fasciculations or action/percussion myotonia. She had a waddling gait, elbow and ankle contractures, and rigid spine (figure 1). The localization in her case could involve anterior horn cells, motor nerve roots, neuromuscular junction, and muscles. Given the childhood onset of symptoms, acquired disorders are unlikely (inflammatory or infiltrative polyradiculoneuropathies, autoimmune disorders of the neuromuscular transmission such as myasthenia gravis or Lambert-Eaton myasthenic syndrome, inflammatory myopathies). The lack of affected family members does not exclude the genetic etiology of the disease. Sensory and motor nerve conduction studies and repetitive nerve stimulations at 2 Hz were normal. Muscle biopsy of the quadriceps (performed previously and reviewed at our institute) showed increased number of fibers harboring single or multiple internal nuclei, fiber splitting, and increased endomysial connective tissue. The above information helped to rule out neurogenic processes, such as disorders of the anterior horn cells, and neuromuscular junction transmission defects, such as congenital myasthenic syndromes. The additional clinical clues that help narrow the differential diagnosis in this case were the early onset of elbow contractures and the rigid spine. Holter monitoring identified 2 brief episodes of atrial fibrillation lasting less than 1 minute, while echocardiogram revealed no evidence for cardiomyopathy. Biopsy of the deltoid muscle showed nonspecific active and chronic myopathic changes (figure e-1 on the Neurology Web site at Neurology. There were no vacuolar changes or other structural abnormalities suggestive of any specific congenital myopathy (nemaline rods, cores, mini-cores, fiber type disproportion, or radial distribution of the myofibrils in association with the internalized nuclei). Two years later, she had a left middle cerebral artery cardioembolic ischemic stroke and was found to be in atrial fibrillation. This variant is predicted to result in an in-frame alteration, consisting of deletion of 3 amino acids and insertion of a missense amino acid (p. The amino acids affected by this deletion in the lamin A protein are all evolutionary conserved across species from human to chimp, nonprimate mammals, chicken, frog, and zebrafish. C), located in the region deleted in our patient, was observed in identical twin brothers with autosomal dominant Emery-Dreifuss muscular dystrophy and cardiomyopathy. Cardiac manifestations in laminopathies range from rhythm and conduction defects, including atrial and ventricular arrhythmias, to dilated cardiomyopathy. Therefore, early diagnosis of laminopathy is essential for proper treatment and prevention of fatal complications. An earlier molecular diagnosis would have resulted in a closer cardiac follow-up and more aggressive cardiac care, which may or may have not prevented the cerebral stroke. Genetic counseling and cardiac evaluation are important for family members due to the risk of fatal cardiac arrhythmias even in asymptomatic individuals. Ghosh: drafting/revising the manuscript, study concept or design, analysis or interpretation of data, accepts responsibility for conduct of research and final approval, acquisition of data. Milone: drafting/ revising the manuscript, study concept or design, analysis or interpretation of data, accepts responsibility for conduct of research and final approval, acquisition of data, study supervision. Cardiac transplantation in twins with autosomal dominant Emery-Dreifuss muscular dystrophy. He had pulmonary sarcoidosis at age 24 years, which remained in remission after treatment with corticotropin and prednisone. Clinical examination showed 4/5 strength of the iliopsoas and quadriceps muscles and slight weakness of the biceps brachii muscles. The results of gait examination, including stance, stride, posture and arm swing, were normal. The rest of the results of the neurologic examination, particularly the sensory examination, were normal. Hereditary spinal muscular atrophy is characterized by proximal muscle weakness but usually presents at an earlier age. Myopathies could be toxic, such as those associated with alcohol, steroid, or statins; metabolic, such as thyroid myopathy and Pompe disease; or inflammatory. In rare cases, genetically determined dystrophinopathies are the cause of limbgirdle weakness at this age. The prevalence of these disorders at older age and the presence of an associated autoimmune disorder should be considered. Needle electromyography of the left rectus femoris muscle showed no abnormalities. Biopsy of a symptomatic anterior tibial muscle showed nonspecific myopathic changes. What is the most likely diagnosis, and does the clinical course help you in the diagnostic process? Steroid myopathy was also unlikely, because the prednisone was stopped several years previously. Over the following years, his muscle weakness progressed and spread to the distal legs and finger flexor of 2 digits of his right hand. He reported difficulties with swallowing solid foods but did not develop fasciculations, cramps, or pyramidal tract signs. Although the prevalence is low (5 to 10 patients per million inhabitants), it is considered one of the most frequently acquired myopathies in the elderly. Most patients present with weakness of quadriceps muscles or finger flexors or dysphagia. The onset is insidious, and the course is slowly progressive, painless, and mostly asymmetric. Some criteria also require positive amyloid staining or 16- to 20-nm tubulofilaments on electromicroscopy. Important clues for quadriceps weakness are difficulties when climbing stairs, repetitive falls on the knees, and difficulty with rising from a chair. There is asymmetric involvement of the adductor muscles, more pronounced on the right side. This case illustrates that the clinical picture was diagnostically more helpful than the histopathologic criteria. Verschuuren has received research support from Prosensa and the Princess Beatrix Foundation. Inclusion body myositis: clinical features and clinical course of the disease in 64 patients. Inclusion-body myositis: a myodegenerative conformational disorder associated with Abeta, protein misfolding, and proteasome inhibition. He had a medical history of hypogonadism, diagnosed 1 year before the onset of the gait disorder, attributed to a bilateral orchiectomy due to a testicular tumor, performed elsewhere when he was 37. His family medical history included pes cavus in his mother and siblings, otherwise unremarkable. Neurologic examination revealed a wide-based spastic gait with positive Romberg sign. Strength was 4/5 in both iliopsoas, and 41/5 in the remaining muscles of the lower limbs, with increased muscle tone. Vibration sensation was decreased in lower limbs, and joint position sense was lost in the toes. A syndrome of this type may be indicative of hereditary spinocerebellar degeneration (Friedrich ataxia) or one of its variants. In middle and late adult life, a slow compression of the spinal cord by spondylosis is a frequent cause of myelopathy. Subacute combined degeneration (vitamin B12 or copper deficiency), spinal arachnoiditis, spinal arteriovenous shunts, and spinal tumors, particularly meningioma, are important diagnostic considerations. Somatosensory evoked potentials revealed an increased latency in the central components of upper limb potentials, and altered potentials in lower limbs. Transcranial magnetic stimulation showed greater delay in the lower than the upper limbs.
